Focal mechanism inversion of the 2018 M_(W)7.1 Anchorage earthquake based on high-rate GPS observation  

作　　者：Yanhao Zhang Caijun Xu Jin Fang Zelong Guo 

机构地区：[1]School of Geodesy and Geomatics,Wuhan University,Wuhan,430079,China [2]Key Laboratory of Geospace Environment and Geodesy,Ministry of Education,Wuhan University,Wuhan,430079,China [3]Key Laboratory of Geophysical Geodesy,Ministry of Natural Resources,Wuhan,430079,China [4]COMET,School of Earth and Environment,University of Leeds,Leeds,LS29JT,UK [5]German Research Centre for Geosciences(GFZ),Section of Remote Sensing,Potsdam,14473,Germany

出　　处：《Geodesy and Geodynamics》2021年第6期381-391,共11页大地测量与地球动力学（英文版）

基　　金：co-supported by the National Natural Science Foundation of China under Grants No.41721003,No.42074007;the National Key Research and Development Program of China under Grant No.2018YFC1503604。

摘　　要：The M_(W)7.1 Anchorage earthquake is the most destructive earthquake since the 1964 M_(W)9.2 great Alaska earthquake in the United States.In this study,high-rate GPS data and near-field broadband seismograms are used in separate and joint inversions by the generalized Cut-and-Paste(gCAP)method to estimate the focal mechanism.In order to investigate the influence of crustal velocity structure on the focal mechanism inversion results,two velocity models(Crustl.0 and Alaska Earthquake Center(AEC))are used for detailed comparison and analysis.The results show that:(1)The two nodal planes of the optimal double-couple solution are nearly north-south striking,with dip angles of about 30°and 60°respectively,and the centroid focal depth is 54-55 km,which is an intraplate normal fault event.(2)The inversion results for the two types of data and the two velocity models are consistent with some previous studies,which indicates that the results are stable and reliable.The more accurate velocity structure model is helpful for focal mechanism inversion of the complex earthquake.(3)The inclusion of high-rate GPS data in joint inversion provides a more effective constraint on centroid depth.

关 键 词：M_(W)7.1 Anchorage earthquake High-rate GPS and seismogram Velocity model Joint inversion Centroid depth 

分 类 号：P228.4[天文地球—大地测量学与测量工程] P315.7[天文地球—测绘科学与技术]